This disclosure relates to xerographic reproduction systems or apparatus, and more particularly to a toner purging development apparatus and a method of producing custom color on demand in a xerographic color machine using same.
Xerocolography (a form of xerography for dry color imaging) is a color imaging architecture which combines multi-color xerographic development with multiwavelength laser diode light sources, with a one polygon, single optics ROS and with a polychromatic, multilayered photoreceptor to provide color imaging in either a single pass or in two passes. Inherently perfect registration is achieved since the various color images are all written at the same imaging station with the same ROS. In all three latent images are written in this manner. Two of the three images are immediately developable because their voltage levels are offset from a background level while the voltage level of the third image is at the time of its formation equal to the background voltage level. Before the third image can be developed, the photoreceptor must be exposed to flood illumination of a predetermined wavelength.
Xerography is capable of producing either highlight color or process color images in a single pass as well as in multiple passes. In conventional tri-level Xerographic process, two color or high light color images at or within a range of about 50 to 90 registered images per minute can typically be produced using particular color toner or developer dedicated development apparatus.
Conventional highlight color dry powder machines offering custom color ordinarily require changing the developer mix, either by removing it entirely from the custom color developer housing, or by removing a given housing charged with a given custom color developer and replacing that housing with another charged with the desired color. Thus an operator ordinarily will risk going through a messy process of removing one color development housing and switching it with color development housing.
There is therefore a need for a toner purging development apparatus and a method of easily producing custom color on demand in a xerographic color machine using same.
In accordance with one aspect of the present disclosure, there is provided a method of, and a toner purging development apparatus for, enabling clean and efficient accomplishment of custom color on demand imaging in a xerographic color machine using two component developer material. The toner purging development apparatus includes (a) a development housing defining a sump holding two component developer material including carrier particles, and a first quantity of toner particles having a first color and a charge having a first polarity; (b) a first set of devices for charging and transporting toner laden carrier particles within the sump; and (c) a second set of devices for transporting the toner laden carrier particles through a development nip of the color reproduction machine. The toner purging development apparatus also includes (d) toner purging apparatus for enabling clean and efficient changing of custom color on demand within the sump by removing the first quantity of toner particles having a first color from the sump, and allowing the loading into the sump of a second quantity of toner particles having a second and different color. The toner purging apparatus as shown is mounted adjacent the movable donor member and includes a corona generating device for detoning the charged toner laden carrier particles forming a first layer of toner particles and a second layer of detoned magnetic carrier particles on the surface of the donor member. The toner purging apparatus further is connected to (e) a controller that is connected to the toner purging apparatus and has a first control mode for controlling the toner purging development apparatus in a development mode, and a second control mode for controlling the toner purging development apparatus in a toner purging mode.